Respiratory mask

ABSTRACT

A respiratory mask, a mould for a respiratory mask, as well as to a method for producing a respiratory mask are disclosed, in which manufacturability and usability of respiratory masks are improved. A respiratory mask is disclosed for administering a breathable gas to a patient, the respiratory mask comprising a first component formed from a flexible material and a second component formed from a material that is more rigid than the flexible material, wherein the first component is formed onto the second component by an overmoulding process.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/093,603, filed Dec. 2, 2013, now allowed, which is a continuation ofU.S. application Ser. No. 11/988,569, filed Jan. 10, 2008, now U.S. Pat.No. 8,596,273, which is the U.S. national phase of InternationalApplication No. PCT/AU2006/001021, filed Jul. 19, 2006, which designatedthe U.S. and claims priority to German Application Nos. 10 2005033650.7, filed Jul. 19, 2005, and 10 2005 033648.5, filed Jul. 19,2005, the entire contents of each of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION 1.0 Technical Field

The invention relates to respiratory masks and manufacturing processesfor respiratory masks. In particular, the invention relates toovermoulding portions of respiratory masks.

It should be noted that the phrase “respiratory mask” in thisspecification includes any type of patient interface, including fullface masks, nasal masks, and nasal prong masks etc.

2.0 Introduction to Respiratory Masks

Respiratory masks are used for administering a breathable gas, such asambient air, at a pressure that is, at least sometimes, above theambient pressure. This is known as Positive Airway Pressure (PAP)therapy, such as Continuous Positive Airway Pressure (CPAP) or VariablePositive Airway Pressure (VPAP) therapy, and may be used for treatingSleep Disordered Breathing (SDB) or other medical conditions.

International Patent Application PCT/EP02/11798, filed by Medizintechnikfur Arzt and Patient (MAP), now ResMed R&D Germany GmbH, discloses arespiratory mask for administering a breathable gas to a user. Thisrespiratory mask makes it possible, when worn by a user, to seal off aninterior volume of the respiratory mask from the environment. Suchrespiratory masks are used particularly in conjunction with medical ortherapeutic administration of breathable gases (and additions thereto,such as drug vapours), as well as in the industrial field, for instancein the field of gas masks and breathing equipment. Typically, theinterior volume is sealed using a sealing cushion or lip structure thatis inwardly curved and extends around an opening in the mask and sealsagainst the user's face. Sealing cushions are generally made from anelastically deformable material, such as silicone and seal bycompression against the user's face. The level of sealing achievedgenerally increases with the contact pressure of the sealing cushionagainst the face.

2.1 Manual Labour

It is known amongst skilled persons that conventional mask systems aredifficult to assemble. Consequently, assembly of components requiressignificant labour time, particularly while assemblers are learning.Further labour is required to check the correct assembly of maskcomponents. Manual labour increases the cost of goods and subsequentlymay decrease the profitability of respiratory mask manufacturers and/ormake masks more expensive for patients.

Automation of the manufacturing assembly process by using robotics, forexample, is difficult due to the often complex manipulations required toassemble mask components. It is also known that flexible components, asare common in masks and mask systems, are exceedingly difficult tohandle robotically. For automation to be achieved a very high level ofrobotic dexterity would be required and the expense of designing,manufacturing and configuring such robotics has generally beenconsidered prohibitive.

2.2 Moulding

In general terms, the greater the number of components a mask includes,the more expensive it is to manufacture because more component mouldsare required.

2.3 Assembly by Patients

Assembly and disassembly of mask components by patients can be difficult(e.g. after washing the mask prior to use). This problem is oftenexacerbated by the often relatively low dexterity of patient's sufferingfrom sleep disordered breathing (e.g. because of age, weight orarthritis). Generally, therefore, the more components a mask has, themore difficult it is for patients to assemble. Furthermore, the higherthe number of mask components, the greater the risk of those componentsgetting lost and the greater the risk of mis-assembly.

2.4 Biological Contamination

Another problem with masks assembled from components that can beseparated by a user is the build-up of biological contaminants in thecrevices between the components, even when the mask is being regularlywashed.

2.5 Mask Comfort

One ongoing problem encountered in mask design is the difficultyassociated with creating a comfortable mask. Ordinary silicone membranesealing technology can feel unpleasant and sometimes lead to pressuresores when the mask in tightened too much for an extended period oftime.

2.6 Mask Aesthetics

It is known that good mask aesthetics can be achieved by a sleek, simpledesign that does not have a ‘busy’ appearance. However, the variousfunctional requirements of masks sometimes impinges on a designersability to design a mask with good aesthetics. This problem can becompounded when masks are made from a relatively large number ofcomponents that do not connect in a smooth, contoured fashion.

BRIEF SUMMARY OF THE INVENTION 3.0 Embodiments of the Present Invention

Embodiments of the present invention seek to address one or more of theabovementioned problems or to at least provide a commercially valuablealternative.

One aspect of the invention relates to a method for manufacturing arespiratory mask wherein at least one step in the manufacturing processis the integral forming of at least two components in or from at leasttwo different materials. Another aspect of the invention relates to arespiratory mask manufactured by the above method.

Preferably, the integral forming is an overmoulding operation which isautomated, for example, by using robotics. Overmoulding may be performedby any known moulding technique, including surface treatment by anyknown treatment, such as plasma treatment. An overmoulding step may beused to mould a flexible component onto a component that is lessflexible than the flexible material (henceforth a “substantially rigidcomponent”). In one embodiment, the mask cushion (e.g., silicone) andframe (e.g., polycarbonate) are co-moulded using one of themanufacturing processes described herein.

As a result, it advantageously becomes possible to create a respiratorymask in which relatively complex geometries of the flexible componentsand of the substantially rigid components coupled to them can berealized. Furthermore, the relatively time-consuming and labourintensive mask manufacturing process can now be either partially orcompletely automated. This advantage arises because one or more maskassembly steps and mask components may not be required because twocomponents (e.g. cushion and frame) are joined during moulding and so donot require subsequent assembly.

In an especially preferred embodiment of the invention, the integralforming of a flexible component onto a substantially rigid component isdone directly in an injection moulding tool. This injection mouldingtool preferably includes multiple cavities.

A liquid silicone rubber (LSR) material is preferably used for theflexible material and a polycarbonate plastic is preferably used for thesubstantially rigid material. In an especially preferred embodiment ofthe invention, the integral forming of the components is carried out insuch a way that the flexible component can be manually separated fromthe substantially rigid component. This allows the flexible component tobe removed as required. It is also possible to accomplish the integralforming such that the flexible component is coupled with thesubstantially rigid component in an intimately adhering way (i.e. thecomponents cannot be manually separated).

In an especially preferred embodiment of the invention, at least one ofthe flexible components of the respiratory mask is a sealing cushion.The sealing cushion is preferably integrally formed onto thesubstantially rigid component in such a way that an intimate adhesivebond results. The bonding geometries of the substantially rigidcomponent and the flexible components as well as other factors may bemanipulated to provide a required level of adhesion.

According to another embodiment of the invention, there is provided arespiratory mask for administering a breathable gas to a patient, therespiratory mask comprising a) a first component formed from anelastomeric material; and b) a second component formed from a materialthat is less flexible than the elastomeric material, wherein the firstcomponent is integrally formed onto the second component.

According to another embodiment of the invention, there is provided arespiratory mask comprising a substrate made of a relatively rigidmaterial, wherein the substrate includes at least one treated portioninclined to accept a reactive substance; and an elastomer that is madeof a relatively more flexible material compared to the relatively rigidmaterial of the substrate, said elastomer being applied to the substrateand secured to the substrate via an induced adhesive bond formed betweensaid treated portion and a surface of the elastomer abutting the treatedportion.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask, comprising: providing anelastomeric material for forming into a first component; providing asecond component that is less flexible than the elastomeric material ina mould; and integrally forming the elastomeric material onto the secondcomponent within the mould in order to form the first component.

The first component can be manually separated from the second component,or the first component is joined to the second component in anintimately adhering manner. The method may further comprise pre-treatingthe second component to strengthen adhesion between the first and secondcomponents. The pre-treating step may comprise applying plasma,preferably an atmospheric plasma treatment, to a bonding surface of thesecond component. Corona treatment is an alternative. The integralforming may be carried out in an injection moulding tool.

According to another embodiment of the invention, there is provided amould for a respiratory mask for administering a breathable gas to apatient, the respiratory mask comprising a first component formed froman elastomeric material; and a second component formed from a materialthat is less flexible than the elastomeric material, wherein the firstcomponent is integrally formed onto the second component, wherein themould comprises a mould cavity in which the first component is mouldedonto the second component.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a maskframe and an elbow provided to the frame, and wherein the elbow or frameincludes at least one selected portion including said substrate, and themethod further comprises overmoulding said elastomer onto the selectedportion.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a maskframe, a cushion provided to the frame and a forehead support positionedabove the frame, wherein the mask comprises a flexible portion couplingthe frame and the forehead support, the flexible portion including astructural member including said substrate and at least one disc or tubeincluding said elastomer.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a maskframe made at least in part from said elastomer and a retaining ringincluding said substrate, wherein the method further includesovermoulding the frame onto the ring.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask comprises a frameand a cushion and a headgear assembly to support the frame and cushion,wherein the headgear assembly includes a yoke associated with a strapand a seal ring provided to the yoke, wherein the yoke includes at leastone selected portion including the substrate and the method comprisesco-moulding the seal ring onto the yoke.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a frameand a gas washout vent having at least one hole or pore, wherein theframe includes at least one selected portion including the substrate andthe method comprises co-moulding the gas washout vent onto the frame.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a framehaving an aperture and a plug provided to close the aperture, the frameincluding at least a selected portion including said substrate and themethod comprise overmoulding the plug onto the frame.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a conduitincluding said substrate and a wall member formed at least in part bysaid elastomer, and said method further comprises overmoulding the wallmember and the reinforcement member.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the frame includes a portportion and a port cap provided to the frame, wherein the port portionincludes at least a selected portion including the substrate and themethod further comprises overmoulding the port cap onto the frame.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein said mask includes a framewith said substrate and a bladder is provided to the frame and formed atleast in part from said elastomer.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a frameincluding at least one port, and nasal cannulae, wherein the frameincludes said substrate and the cannulae are formed at least in partfrom the elastomer, the cannulae being in communication with the port.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a frame, acushion, a forehead support positioned above the frame, and a foreheadpad provided to the forehead support, the forehead pad including saidelastomer and the forehead support including said substrate.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a maskframe including the substrate and a mask cushion including theelastomer, wherein the frame includes a peripheral region and thecushion includes a T-shaped or L-shaped rim overmoulded to the frame.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a maskframe including the substrate and a mask cushion including theelastomer, in which the mask frame and the mask cushion form at leastone of a diagonal joint, a lap joint and/or a V-joint.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a frameand a cushion, the cushion having an expandable bladder having aninterior defined by an interior surface of the elastomer and a portionof the frame that is not treated, and the frame includes a port to allowintroduction of a substance delivered to the interior to expand thebladder.

According to another embodiment of the invention, there is provided amethod for manufacturing a respiratory mask comprising forming asubstrate made of a relatively rigid material; and overmoulding anelastomer to or with the substrate, wherein the mask includes a maskframe a cushion and a cushion clip to secure the cushion to the frame,wherein the substrate is provided as part of the cushion clip and thecushion includes the elastomer.

According to another embodiment of the invention, there is provided ahumidifier tub for a flow generator comprising a substrate made of arelatively rigid material, wherein the substrate includes at least onetreated portion inclined to accept a reactive substance; and anelastomer that is made of a relatively more flexible material comparedto the relatively rigid material of the substrate, said elastomer beingapplied to the substrate and secured to the substrate via an inducedadhesive bond formed between said treated portion and a surface of theelastomer abutting the treated portion wherein the humidifier tubincludes a lid having said substrate and a seal made in part from saidelastomer.

According to another embodiment of the invention, there is provided amethod for manufacturing a humidifier tub comprising forming a substratemade of a relatively rigid material; and overmoulding an elastomer to orwith the substrate, wherein the humidifier tub includes a lid havingsaid substrate and a seal made in part from said elastomer.

According to another embodiment of the invention, there is provided ahumidifier tub comprising a substrate made of a relatively rigidmaterial; and an elastomer overmoulded with or to the substrate, whereinthe humidifier tub includes a lid having said substrate and a seal madein part from said elastomer.

These and other aspects will be described in or otherwise apparent fromthe following detailed description of embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to theaccompanying exemplary drawings, in which:

FIG. 1 is a side, partial cross-sectional view of a respiratory maskaccording to a first embodiment of the present invention shown in situon a patient's face;

FIG. 2 is a cross-sectional perspective view of a respiratory maskaccording to a second embodiment of the present invention;

FIG. 3 is a cross-sectional perspective view of an enlarged portion ofthe frame/cushion interface of the respiratory mask of FIG. 2 andillustrates the bonding configuration therebetween;

FIG. 4 is a cross-sectional perspective view of an enlarged portion ofthe frame of the respiratory mask of FIG. 2 and illustrates an elastomercomponent disposed over and bonded around a peripheral frame channel andin an inwardly disposed configuration;

FIG. 5 is a cross-sectional perspective view of an enlarged portion ofthe frame of the respiratory mask of FIG. 4 and illustrates theelastomer component in an outwardly disposed configuration;

FIG. 6 is a schematic, side, cross-sectional view of a cushion to frameconnection according to a third embodiment of the present invention;

FIG. 7 is a side, partial cross-sectional view of the respiratory maskof FIG. 1 and illustrates the forehead pad in cross-section;

FIG. 8 is a side, partial cross-sectional view of the respiratory maskof FIG. 1 and illustrates a flexible portion between the frame andforehead support according to an embodiment of the present invention;

FIG. 9 is a side, partial cross-sectional view of a respiratory maskaccording to a fourth embodiment of the present invention andillustrates a flexible portion that incorporates a conduit sectiontherethrough;

FIG. 10 is a perspective exploded view of a respiratory mask frame,elbow and elbow retaining clip according to a fifth embodiment of thepresent invention illustrating a bonded elastomer sealing portion on theelbow;

FIG. 11 is a perspective exploded view of a respiratory mask frame,elbow and elbow retaining clip according to a sixth embodiment of thepresent invention illustrating a number of additional bonded elastomersealing portions on the socket and retaining clip;

FIG. 12 is a perspective exploded view of an elbow of a respiratory maskaccording to a seventh embodiment of the present invention illustratinga number of bonded elastomer sealing portions;

FIG. 13 is a perspective view of a portion of a respiratory mask frameand elbow according to a eighth embodiment of the present invention;

FIG. 14 is a perspective, cross-sectional view of the portion of theframe and elbow of FIG. 13;

FIG. 15 is an enlarged, perspective, cross-sectional view of the frameand elbow of FIG. 13 illustrating the elbow sealing arrangement;

FIG. 16 is a perspective view of a portion of a respiratory mask frameand elbow according to a ninth embodiment of the present invention;

FIG. 17 is a perspective, cross-sectional view of the portion of theframe and elbow of FIG. 16;

FIG. 18 is an enlarged, perspective, cross-sectional view of the elbowof FIG. 16 illustrating the elbow sealing arrangement;

FIG. 19 is a perspective, cross-sectional view of a portion of therespiratory mask frame and elbow of FIG. 16;

FIG. 20 is a perspective view of a portion of a respiratory mask frameand elbow according to an tenth embodiment of the present invention;

FIG. 21 is a perspective, cross-sectional view of the portion of theframe and elbow of FIG. 20;

FIG. 22 is an enlarged, perspective, cross-sectional view of the frameand elbow of FIG. 20 illustrating the elbow sealing arrangement;

FIG. 23 is a perspective view of a portion of a respiratory mask frameand elbow according to a eleventh embodiment of the present invention;

FIG. 24 is a perspective, cross-sectional view of the portion of theframe and elbow of FIG. 23;

FIG. 25 is an enlarged, perspective, cross-sectional view of the frameand elbow of FIG. 23 illustrating the elbow sealing arrangement;

FIG. 26 is a perspective view of a portion of a respiratory mask frameand elbow according to a twelfth embodiment of the present invention;

FIG. 27 is a perspective, cross-sectional view of the portion of theframe and elbow of FIG. 26;

FIG. 28 is an enlarged, perspective, cross-sectional view of the frameand elbow of FIG. 26 illustrating the elbow sealing arrangement;

FIG. 29 is a perspective view of a portion of a respiratory mask frameand elbow according to an thirteenth embodiment of the presentinvention;

FIG. 30 is a perspective, cross-sectional view of the portion of theframe and elbow of FIG. 29;

FIG. 31 is an enlarged, perspective, cross-sectional view of the frameand elbow of FIG. 29 illustrating the elbow sealing arrangement;

FIG. 32 is a perspective, exploded view of an elbow and a frame having aflexible enclosure, a rigid elbow connection ring defining an aperturein the frame and a rigid surrounding portion according to a fourteenthembodiment of the present invention;

FIG. 33 is a perspective, exploded view of an elbow, frame and headgearmember according to a fifteenth embodiment of the present invention;

FIG. 34 is a side, partial cross-sectional view of a respiratory maskaccording to a sixteenth embodiment of the present invention andillustrates a vent;

FIG. 35 is a perspective exploded view of a respiratory mask frame andvent plug according to a seventeenth embodiment of the presentinvention;

FIGS. 36(a)-36(d) are schematic diagrams showing three types of conduitreinforcing structure according to eighteenth, nineteenth, twentieth andtwenty first embodiments of the present invention, respectively;

FIG. 37 is a side, cross-sectional view of a ports cap configured on aframe of a respiratory mask according to a twenty-second embodiment ofthe present invention;

FIG. 38 is a perspective, exploded view of a frame, elbow and elbowretaining clip including a plurality of gripping portions according to atwenty third embodiment of the present invention;

FIG. 39 is a perspective view of a frame including a large grippingportion according to a twenty-fourth embodiment of the presentinvention;

FIG. 40 is a perspective view of a frame including a detachable conduitarrangement according to a twenty-fifth embodiment of the presentinvention;

FIG. 41 is a perspective view of a flow generator including a humidifiertub having a lid according to a twenty-sixth embodiment of the presentinvention;

FIG. 42 is a perspective view of the lid of FIG. 41 showing a recessconfigured to receive a seal;

FIG. 43 is a perspective view of a lid seal for the lid of FIG. 41;

FIG. 44 is a non-vented full face mask according to an embodiment of thepresent invention;

FIG. 45 is a schematic cross-sectional view of a portion of FIG. 44showing an elbow-to-frame interface/seal according to a first variant;

FIG. 46 is a schematic cross-sectional view of a portion of FIG. 44showing an elbow-to-frame interface/seal according to a second variant;

FIG. 47 is a schematic cross-sectional view of a portion of FIG. 44showing an elbow-to-frame interface/seal according to a third variant;

FIG. 48 is a perspective view of an elbow having elastomer sealsaccording to an embodiment of the present invention;

FIG. 49 is an exploded perspective view of a test ring having a seal forinsertion within a receptacle according to an embodiment of the presentinvention;

FIGS. 50-53 illustrate partial cross-sectional views of plug sealsaccording to embodiments of the present invention; and

FIG. 54 illustrates a schematic diagram of a mould system according toan embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS OF THE INVENTION 5.0Introduction 5.0.1 Definitions 5.0.1.1 “Overmoulding”

The word “overmoulding” is used in this specification in its broadestsense, that is, in the sense of moulding one component onto anothercomponent, or integrally forming two components. A number of differentmoulding processes that are deemed to fall within the ambit of the word‘overmoulding’ as used in this specification are described below. Itshould be appreciated that this group of moulding processes is inclusiveand not exhaustive.

Overmoulding is used to refer to the process of forming a bond between afirst material, known as the “substrate material”, and a second materialknown as the “overmould”. However, the word ‘overmoulding’ also refersto moulding where no bond or substantive bond is formed but whererespective components are held together, for example, only by amechanical interlocking, keying or undercut. Mechanical interlocking canbe either macroscopic (e.g., undercuts) or microscopic (e.g., dependingon abrasion of the substrate).

The word ‘overmoulding’ also refers to a type of moulding where the twomaterials to be joined are inserted into the mould at the same time orat two points in time close together. For example, overmoulding includes“overmoulding” or “co-injection moulding”. A co-injection mouldingprocess involves a first step where a first component (e.g., substrate)is moulded in a first mould and once ejected progresses to a second stepwhere the first component is placed inside a second mould for themoulding of a second component (e.g., elastomer) on to it. In betweenthe moulding steps, the first component may be treated to more readilyaccept a reactive substance. Treatment may take the form of plasmatreatment, for example, and this treatment may take place within themould(s) or outside the moulds. What distinguishes co-injection mouldingfrom other types of overmoulding is that when the first component isbeing progressed through the second step another first component isbeing manufactured by the first step. That is, the first and secondsteps are being performed simultaneously for sequentially manufacturedproducts. This can be achieved with a rotating tool set (e.g., aturntable with two or more moulding stations) or robotic arm.

‘Overmoulding’ also refers to “Moving Cores Moulding” where oneinjection moulding machine fitted with two injection systems is used.Once the substrate has cooled sufficiently a section of the toolretracts, forming a cavity for the overmould material. Moving cores haveconventionally been best suited to simple overmoulds, where a uniformthickness of overmould is required.

“Rotating Platen or Stripper Plate” moulding is also considered aovermoulding process. This process involves rotation of the tool oncethe substrate has cooled. A rotating platen rotates the component on itscore, whereas a rotating stripper plate lifts the component off its corebefore rotating. The main advantage of these methods is that they allowa different shaped cavity or core to be used to form the overmould. Moresophisticated components can be created using this method.

5.0.1.2 “Flexible Material/Component”

The words “flexible material/component” as used in this specificationinclude any material with physical properties similar to or the same asan elastomer material which is defined in the Webster's New WorldDictionary as, “a rubber-like synthetic polymer, as silicone rubber”.Therefore, a rubber, a natural polymer or any other rubber-like materialincluding some gels are included within the scope of the words “flexiblematerial/component”.

The words “flexible material/component” also refer to various mixturesof individual elastomer components. These elastomers may be pre-mixed ormixed in the mould. Examples of elastomers are liquid silicone rubber(LSR), solid silicone rubber and thermoplastic elastomers (TPEs).

5.0.1.3 “Substantially Rigid Component”

A substantially rigid component includes all materials that are lessflexible than the flexible material. Examples of substantially rigidcomponents are polycarbonate (e.g. Lexan) and phenol formaldehyde (e.g.Bakelite.)

5.0.2 Bonding

There are 2 main types of bond: adhesive (an interfacial property) &cohesive (a bulk property). This application is largely concerned withthe former rather than the latter.

There are several different types of adhesive bonding:

-   -   adsorption bonding depends on intermolecular attractive forces        between adhesive and substrate (e.g. Van der Waals forces)    -   chemical bonding depends on available functional groups on the        substrate surface and their reactivity with the molecules of the        adhesive. Also known as covalent bonding.    -   diffusion bonding depends on the mutual solubility between the        substrate and adhesive    -   electrostatic bonding depends (typically for solids) on        dipole-dipole interactions.

Ideally, the adhesive strength of the bond formed in embodiments of theinvention is significantly greater than the cohesive strengths of thecomponents thereof. The level of adhesion achievable is dependant on thepreparation of the bonding surface areas, amongst other factors. Apretreatment may be applied to a selected bonding area of thesubstantially rigid component to enhance adhesion.

One such pretreatment is the application of plasma, such as anatmospheric plasma treatment, to the bonding area of the substrate.Plasma treatment chemically activates the bonding area to enhancechemical bonding. Plasma treatment is effected by blasting highlyenergized gases at the surface which causes reactive molecules to beembedded in the surface. These molecules form a bond with the relativelyless rigid component, e.g., in the case of silicone, a polydimethylsiloxane bond may be formed. The gas is typically compressed air, but itcan be nitrogen or other gases. It should be noted that the longer aplasma treated surface is left before bonding, the less effective thetreatment will be. Plasma treatment is described in “Plasma Processesand Polymers” by d'Agostino et al., published by Wiley, 2005.

One method of applying plasma treatment is to position a masking sheetor stencil over the surface to which the plasma is to be applied. One ormore aperture(s) in the stencil allows the plasma to contact the portionof the surface to be bonded but masks the remainder of the surface. Analternative to use of a masking sheet is the use of a finelycontrollable plasma gun (e.g. a gun mounted on an apparatus controllableby a computer such as a robotic arm).

Examples of commercially available atmospheric plasma guns includeAtomflo™ by Surfx Technologies LLC of USA and PlasmaTEC™ by DyneTechnology Ltd of UK.

One alternative to plasma treatment is corona treatment, which typicallyis a stronger treatment which requires more energy and affects thesubstrate differently.

A further alternative to plasma treatment is chemically treating thesurface by, for example, the application of adhesion promoters, such assilane coupling agents. Another chemical pre-treatment is theapplication of a solvent to the surface.

Yet another alternative is to use self-adhesive elastomeric material andto apply a non-bonding material (e.g. silicone grease) or contaminant,where a bond is not desired.

A further variation is flame oxidization of the surface.

Advantageously, all these pre-treatment processes allow treatment ofonly selected areas as required, by masking or otherwise avoiding areaswhere bonding is not desired.

Adhesion strength is also dependant on timing. A better bond may beformed when the second component is moulded onto the first component ifthe temperature of the first component is still raised. In the case thata chemical bond is not required, temperature differences and theresulting shrinkage differential may improve mechanical interlocking.

Often when an overmoulding process is used, the substantially rigidcomponent will be moulded with a slight recess around the periphery ofthe bonding area to assist bonding with the flexible material byproviding a level of mechanical interlocking as well as a larger bondingarea. Furthermore, bonding along multiple planes with respect to forcesapplied may assist in reducing adhesive failure.

5.1 General Structure of a Respiratory Mask

A respiratory mask 2A is shown in FIG. 1 in situ on the face of a user1000. The mask 2A comprises a frame 4A, formed from a substantiallyrigid component, such as a polycarbonate material, a sealing cushion 6Aformed from an elastomeric material, such as liquid silicone rubber(LSR), and a forehead support 8A, which is adjustably coupled to theframe 4A via a flexible portion 10A. The forehead support 8A includes aforehead pad 12A, made from an elastomeric material.

5.2 Sealing Cushion

The cushion 6A has been co-moulded onto a peripheral portion 14A of theframe 4A. In this example, the frame 4A was pretreated such that thecushion 6A forms a high-strength adhesive bond with the frame 4A.

The cushion 6A includes a lip 16A that is curved inwardly and terminatesin an aperture 18A that is sized and shaped for receiving at least partof the nose of a patient. The lip 16A traverses an upper lip region 1002of the user 1000 in the case that the mask 2A is configured as a nasalmask or a chin region 1004 of the user 1000 in the case that the mask 2Ais configured as a full-face mask. Although the mask 2A onlyincorporates a single lip 16A, it should be appreciated that multiplelips could be incorporated. Gel structure(s) may also be incorporatedinto lip 16A, or in the case that multiple lips are provided into eachlip. Alternatively, the lip 16A could be replaced with one or more gelstructures.

Moulding the cushion 6A to the frame 4A eliminates the need for acushion-to-frame securing component and the associated assembly step.This reduces the cost of goods and/or may assist in improving compliancewith therapy.

5.2.1 Bonding Configurations

Various bond configurations are possible. In one embodiment, shown inFIGS. 2 and 3, the cushion 6B of a respiratory mask 2B has a T-shapedrim 20B that is sized to be bonded to a peripheral region 22B of theframe 4B. The T-shaped rim 20B provides a bonding surface 24B that islarger than it would otherwise be if no T-shaped bonding rim 20B wasprovided. This larger bonding surface 24B allows a stronger bond toform. Alternatively, an L-shaped bonding rim could be provided. However,the T-shaped bonding rim 20B is advantageous with respect to theL-shaped rim because when the cushion 6B is pulled away from the frame4B, no bending moment is created. A bending moment could assist a teardeveloping through the bond. Other suitable bonding configurationsinclude a diagonal joint, a lap joint and a V-joint. Furthermore, thebonding could occur on an interior surface of frame 4B, e.g., a lapjoint.

5.2.2 Bonding to Form Bladders

Referring to FIGS. 4 and 5, selective bonding can be utilized to form abladder 26B that can be expanded. The bladder 26B can be expanded bydelivery of pressurized air to a port 30B. The stenciling or maskingprocedure described in Section 5.0.2 may be utilized to chemicallyactivate bonding areas 32B where sides of the wall 34B of the bladder26B join the frame 4B. The bonding areas 32B adhere to the portions ofthe cushion in contact with the bonding areas, while the surface of thebladder 26B is free to separate from the frame 4B since those portionsof the frame have not been treated. The pressurized air may bepressurized to 2 bar or any other suitable pressure. Furthermore, gasesother than normal air could be used to pressurize the bladder 26B.Alternatively, a gel, foam, liquid or other soft substance may beinserted into the bladder 26B instead of a gas, such that a soft,flexible pad is formed. The pad may be filled and permanently sealed orbe releasably or temporarily sealed. The inside surfaces of the pad maybe provided with a permeation-resistant liner.

In one embodiment, the gel cushion could be provided using a skin madeof LSR that is filled with a gel, e.g., silicone. To prevent the gelfrom permeating through the LSR skin, the inside surface of the skincould be coated with a liner, such as polyester and/or polyurethane. Theliner could be applied using any number of techniques, e.g., spraying(just before the gel is introduced, e.g., in FIG. 5), co-moulding,dipping, brushing, etc.

Referring to FIG. 6, an alternative reinforced bladder arrangement 36Cis shown. In this arrangement the cushion 6C is not directly formed ontothe frame 4C but is co-moulded to a clip 38C. The clip 38C is attachableto the frame 4C by a mechanical interlock. The cushion 6C may also bebonded to the clip 38C in a manner such that when attached to the frame4C, a portion of the cushion 6C is sandwiched between the frame 4C andclip 38C providing a mechanical interlock. The clip 38C is configuredwith a reinforcing member 40C for supporting and stabilizing an undersurface 42C of the cushion 6C. This limits rotation/movement of thecushion 6C on the face of the user.

5.3 Forehead Support

Referring now to FIG. 7, the forehead support 8A and forehead pad 12Amay be embodied as co-moulded components. The forehead pad 12A is formedby injection-moulding an elastomeric material onto the forehead support8A which is made from a dimensionally stable plastic material, such as apolycarbonate. A slot 44A is formed in the forehead pad 12A during theovermoulding process by virtue of the shape of the forehead support 8A.The slot 44A provides a mechanical interlock such that the foreheadsupport 8A can be releasably secured to the forehead support 8A. Thereis no intended or significant adhesive bond between the forehead support8A and forehead pad 12A in this embodiment. This may be achieved by notusing a surface pre-treatment and/or overmoulding the parts once theforehead support 8A is completely set (i.e. after moulding). The benefitof not including a substantive bond in this instance is that theforehead support can be removed for separate cleaning or replaced with anew or different type of forehead support.

Advantageously, overmoulding the forehead pad 12A to the foreheadsupport 8A eliminates the assembly step of mounting the forehead pad 12Ato the forehead support 8A, reducing the cost of goods and increasingconvenience to the patient.

5.4 Flexible Portion

The flexible portion 10A will now be described with reference to FIG. 8.The flexible portion 10A comprises a structural spine 50A and a numberof elastomer discs 52A that have been co-moulded onto the spine 50A andbetween the frame 4A and the spine 50A. Because the elastomer discs 52Aare flexible, the frame 4A is able to articulate with respect to theforehead support 8A. The elastomer discs 52A may be made from the sameelastomer material that the cushion 6A is made out of or from adifferent flexible material. In an alternative embodiment the elastomerdiscs 52A comprise bladders formed from an elastomeric material (orotherwise) that are filled with a compressed gas, liquid or soft solidsuch as foam, gel or mineral particles.

FIG. 9 shows another embodiment of a mask 2D having a flexible portion10D including an elastomer tube 56D around which a less flexibleexoskeleton 58D is disposed. The ends 60D & 62D of the elastomer tube56D have been comoulded to the frame 4D and forehead support 8D,respectively. This arrangement allows the frame 4D to articulate withrespect to the forehead support 8D, and consequently, the cushion 6D torotate and move to a degree with respect to the patient's face. Thismeans that the mask 2D is able to provide a better seal against thepatient's face. This elastic deformation behavior can be varied bychanging the wall thickness or wall section of the exoskeleton 58D.

The elastomer tube 56D may be made from the same elastomer material thatthe cushion 6D is made out of or from a different flexible andco-mouldable material.

In this case, the elastomer tube 56D provides a fluid passageway thatextends between an inner region of the frame 4D and the forehead support8D where the fluid passageway terminates in a connection 66D. Theconnection 66D is adapted for receiving one end of a conduit (not shown)that is in fluid communication with an outlet port of a flow generator(not shown).

A mask in accordance with other embodiments of this invention mayinclude a translatable adjustment rather than a rotatable adjustment.

5.5 Elbow & Frame Socket

Referring to FIG. 10, a mask 2E is shown which has a frame 4E thatcomprises a socket 68E that is adapted to receive a first end 70E of anelbow 72E. The first end 70E of the elbow 72E is swivel mounted to thesocket 68E and the elbow 72E provides fluid communication between aconduit (not shown) and the mask 2E. A clip 74E is provided to the firstend 70E of the elbow 72E to retain it in the socket 68E in use.

In FIG. 10 the second end 76E of the elbow 72E has an elastomer portion76E co-moulded thereto to provide an improved connection and seal withthe conduit to which it is attached. In an alternative embodiment (notshown), the conduit has an elastomer sealing portion rather than thesecond end 76E.

Referring to FIG. 11 the socket 68G has a dimensionally rigid materialportion 78G and an elastomer portion 80G co-moulded onto an innersurface thereof. The elastomer portion 80G provides a better seal withthe first end 70G of the elbow 72G in use. The clip 74G also includes anelastomer portion 88G co-moulded thereon. This provides a moreacoustically pleasing clipping sound.

FIG. 12 illustrates an elbow 72H generally similar in design andconstruction to the elbow of FIGS. 10 & 11 in its component parts. Theelbow 72H features a number of elastomer portions 90H that serve to aidsealing, dampening, the reduction of rattle and/or the tactility andacoustics of connecting parts.

A number of different elbow-to-frame sealing arrangements will now bedescribed. These are suitable for use on a variety of masks. Followingthis a sealing elbow arrangement for the ResMed Meridian mask [U.S.Provisional Patent Application No. 60/682,827] and a sealing arrangementfor the ResMed Swift mask [U.S. Provisional Patent Application No.60/734,282] will be described, each incorporated by reference in itsentirety.

5.5.1 Two Stage Radial Elbow to Frame Seal A

FIGS. 13 to 15 show a two stage radial seal 92I comoulded to an elbow72I and adapted to seal against a frame 4I. The seal 92I comprises along elastomer lip 941 that abuts an inner surface 84I of a socket 68Iof a frame 4I. The seal 92I further comprises two shorter lips 96I thatare moulded in the line of draw. In use, the long lip 94I presses intothe socket 68I and flexes back onto the two shorter lips 96I such thatthe long lip 94I is supported in a position where it abuts and sealsagainst the socket 68I. This geometry accommodates misalignment of theelbow 72I with respect to the frame 4I.

The elbow 72I further incorporates three circumferential flanges. Afirst flange 98I is integrally moulded to the elbow 72I to prevent theseal 92I from contacting any flat supporting surface when the elbow 72Iis disassembled from the frame 4I. This minimises risk of damage to theseal 92I during transport, storage and cleaning. A second flange 100I isprovided on the elbow 72I and engages the socket 68I to stabilize theelbow 68I. While in this embodiment the second flange 100I is locatedinboard from the seal 92I, in other embodiments it could be movedoutboard providing a greater moment arm. A third flange 1021 ispositioned within the socket 68I to engage a shoulder 103I of the elbow41, adjacent where the socket 68I begins to extend beyond the outersurface 104I of the frame 4I.

Another embodiment (not shown) is also provided where only a linecontact seal is provided to the frame 4I as opposed to an area contactseal. A line contact seal reduces the torque required to rotate theelbow with respect to the frame.

It should also be noted that this design avoids undercuts and crevicesto ensure ease of cleaning.

FIG. 13 also depicts an anti-asphyxia valve having a base portion 103Ithat is co-moulded to an elbow clip 105I of the elbow 72I. Thisovermoulding step replaces an assembly step reducing the cost of goodsand increasing convenience to the patient.

5.5.2 Two Stage Radial Elbow to Frame Seal B

The embodiment shown in FIGS. 16 to 19 includes a seal 106J that issimilar to the seal 92I of FIGS. 13-15 except that the seal geometry hasbeen altered to provide less contact area between the seal 106J and theframe 4J. The seal 106J comprises a long elastomer lip 94J and oneshorter lip 96J that are moulded in the line of draw. The long lip 94Jpresses into the socket 68J of the frame 4J and flexes back onto theshorter lip 96J such that the long lip 94J is supported in a positionabutting and sealing with the inner surface 84J of the socket 68J. Thisgeometry accommodates misalignment of the elbow 72J with respect to theframe 4J.

The elbow 72J incorporates three circumferential flanges to stabilizethe elbow 72J within the socket 68J. A first flange 98J is positionedoutside the socket 68J and frame 4J. The first flange 98J prevents theseal 106J from contacting any flat surface when the elbow 72J isdisassembled from the frame 4J thereby reducing the risk of damage tothe seal 106J during transport, storage and cleaning. A second flange100J is positioned outside the socket 68J and inside the frame 4J andabuts the socket 68J to stabilize the elbow 68J. A third flange 102J ispositioned within the socket 68J adjacent where the socket 68J begins toextend beyond the outer surface 104J of the frame 4J.

Another embodiment (not shown) is also provided where only a linecontact seal is provided to the frame 4J as opposed to an area contactseal. A line contact seal reduces the torque required to rotate theelbow with respect to the frame.

This design avoids undercuts and crevices to ensure ease of cleaning.

5.5.3 Single Radial Seal

Referring to the mask 2K of FIGS. 20-22 an elbow 72K is provided havinga single radial lip seal 108K that acts on an inner surface 84K of asocket 68K. The elbow 72K incorporates four circumferential flanges tosupport and stabilize the elbow 72K on the frame 4K. A first flange 98Kis positioned outside the socket 68K and frame 4K. A second flange 100Kis positioned outside the socket 68K and inside the frame 4K. A thirdand fourth flange, 102K & 110K respectively, are positioned on eitherside of the seal 108K. This design avoids undercuts and crevices toensure ease of cleaning.

5.5.4 Double Radial Seal

FIGS. 23 to 25 show a mask 2L incorporating a double radial seal 112L.The double radial seal 112L has two lips 114L & 116L, respectively,adjacent each other, that seal against an inner surface 84L of a socket68L of a frame 4L. Each lip 114L, 116L is configured with a generallytriangular cross-section such that it has a degree of stiffness toenhance sealing.

The elbow 72L incorporates three circumferential flanges 98L, 100L &102L that are arranged in the same fashion as the embodiment of Section5.5.1 and FIGS. 13-15. This design avoids undercuts and crevices toensure ease of cleaning.

5.5.5 External Seal

The embodiment shown in FIGS. 26-28 provides 3 sealing zones between theelbow 72M and the socket 68M. The 3 sealing zones include a radial seal114M disposed on the elbow 72M inside the socket 68M, an axial seal 116Mthat seals against an end face 118M of the socket 68M and an externalradial lip seal 120M that seals against an outside the socket 68M.

The elbow 72M incorporates four circumferential flanges 98M, 100M, 102Mand 103M to stabilize and support the elbow 72M within the socket 68M.Additionally, the first flange 98M of the circumferential flanges issized and adapted to prevent the seal 120M from contacting any flatsupporting surface when the elbow 72M is disassembled from the frame 4M.This minimises risk of damage to the seal 120M during transport, storageand cleaning.

5.5.6 Radial & Axial Seal Combination

Referring to FIGS. 29-31 a sealing arrangement 122N is shown. Thesealing arrangement 122N comprises a radial lip seal 124N of triangularcross-section that seals against an inner surface 84N of the socket 68Nand an axial lip seal 126N that seals against an end face 118N of thesocket 68N.

The elbow incorporates the same arrangement of three circumferentialflanges for stabilization of the elbow 72N within the socket 68N as isprovided in the embodiment of FIGS. 13-15 described in Section 5.5.1.

5.5.7 ResMed Meridian Mask [U.S. Patent Application No. 60/682,827]

The contents of U.S. Patent Application No. 60/682,827 are incorporatedherein by reference in their entirety. Referring to FIG. 32, the ResMedMeridian Mask Assembly 2O comprises a flexible silicone frame 4O havinga hard peripheral portion 127O, a polycarbonate elbow 72O and aretaining ring 128O that is used to connect the frame 4O to the elbow72O and allow them to swivel relative to each other.

The elastomer frame 4O can be overmoulded to the retaining ring 128O.This ameliorates any difficulties encountered in mounting the ring 128Oon the frame 4O and takes away the step of connecting the two partsduring assembly.

5.5.8 ResMed Swift Mask Elbow [U.S. Patent Application No. 60/758,200]

The contents of U.S. Patent Application No. 60/758,200, filed Jan. 12,2006 are incorporated herein by reference in their entirety. Referringto FIG. 33, a portion of a ResMed Swift Mask 2P is shown including acushion assembly 6P, yoke 130P that is attached to a headgear strap,seal 132P and elbow 72P. The yoke 130P includes a yoke ring 134P that isadapted to surround a portion of the seal 132P and the seal 132P isadapted to surround a portion of the elbow 72P. The cushion assembly 6Pmay be adjustably rotated with respect to the yoke 130P.

Seal 132P may be overmoulded to the yoke ring 134P. This amelioratesdifficulties sometimes encountered in mounting the seal 132P on the yokering 134P and takes away the step of connecting the two parts duringassembly.

5.6 Gas Washout Device

Referring to FIG. 34, the frame 4P includes a co-moulded vent 54P forallowing exhaled breath to exit an interior region of the frame 4P intothe surrounding environment. The vent 54P is formed from an elastomermaterial that has been co-moulded to the frame 4P. The geometry of theframe 4P and vent 54P are such that they mechanically engage in a mannerthat allows the vent 54P to be retained or removed from the frame 4P, asrequired.

In another embodiment, the vent 54P is substantially inseparably coupledto the frame 4P by a chemical bond in addition to the mechanicalinterlock. The vent may also be embodied as an insert that comprises aplurality of fluid conduits (or vent holes or pores (e.g., sintering))that connect the interior region of the frame 4P to the surroundingenvironment.

5.6.1 Sealing a Vented Mask to Make a Non-Vented Mask

FIG. 35 depicts a vented mask 2Q having a vent aperture 54Q and a plug136Q. For ease of visualization FIG. 35 shows the plug 136Q separatelyfrom the mask 2Q but in reality the plug 136Q is formed in the vent 54Qby overmoulding to form a non-vented mask. In this case, the plug 136Qis formed from silicone.

This process means that a single mask frame 4Q is a suitable componentfor either a vented or a non-vented mask. This reduces manufacturingcosts because only one frame 4Q needs to be moulded for both types ofmask.

In the case that non-vented therapy is being delivered to a patient, theplug 136Q is permanently attached to the frame 4Q. Advantageously, thisavoids user interference with the equipment (e.g. removal of the plug136Q) and subsequent therapy problems. This permanent attachment may beachieved through the aforementioned plasma pre-treatment. Alternatively,the plug 136Q may be temporarily attached, and in this case the mask 2Qcould be used to provide either vented or non-vented therapy.

5.7 Conduit

Methods of conduit manufacture utilizing overmoulding will now bedescribed. The fundamental technical issues addressed by theovermoulding technique in the context of conduits is the development ofa conduit which is both flexible yet does not occlude in use.Overmoulding allows a flexible membrane conduit wall to be attached orbonded to a less flexible conduit structure, the purpose of which is toprevent occlusion of the flexible wall.

In one embodiment, the conduit structure is configured as areinforcement structure, e.g., an exoskeleton over/within, and/or insidethe flexible conduit wall. Clearly, where the conduit structure extendscontinuously along the conduit wall, the conduit structure must beformed of a flexible material to allow the conduit to bend. Fastening ofthe flexible wall to the conduit structure may be achieved by eithermechanical engagement, molecular bonding or both.

Three embodiments of conduit structures are shown in FIGS. 36(a)-36(c).The first, shown in FIG. 36(a), is a helical conduit structure 140S thatprovides significant torsional strength. The second conduit structure140T, shown in FIG. 36(b), comprises a plurality of circular ribs 142Tinterconnected by longitudinal members 144T that are provided onalternating opposing sides of the conduit wall (not shown). FIG. 36(c)depicts a third conduit structure 140U comprising a plurality ofcircular ribs 142U interconnected by dual longitudinal members 144U thatare provided on opposing sides of the conduit wall (not shown). FIG.36(d) depicts a fourth conduit structure 145.

5.8 Ports Cap

FIG. 37 shows a ports cap 146V co-moulded to the frame 4V. The ports cap146V comprises a cover portion 148V and a hinge portion 150V that ispermanently bonded to an adhesion region 152V of the frame 4V. The coverportion 148V is only lightly or marginally bonded to the frame 4V andcan be readily manually separated by a user or clinician the first timethe ports cap 146V is used. Advantageously, the ports cap 146V cannot bedropped by a patient or lost. The ports cap 146V can be designed so thatit can be reattached to the frame 4V even though the light bond isbroken (e.g. by a mechanical interlock such as a rib and groovearrangement).

5.9 Mask Surfaces 5.9.1 Gripping

Manual gripping of mask parts made of hard materials with smoothsurfaces (e.g. polycarbonate) can be difficult. This can lead toslippage or movement during manipulation of mask parts. The integrationof elastomeric regions onto a mask, and in particular onto a mask frame,assists both manual and robotic gripping. Elastomeric regions may beintegrated into a mask solely for this purpose and may provide robotswith a controlled grip to handle mask parts for automation, assembly orpackaging purposes.

An example of how gripping regions might be incorporated into a maskframe 4W and elbow 72W is illustrated in FIG. 38. A number of smallgripping regions 152W are co-moulded onto each side of the frame 4W andat least one relatively large gripping region 154W is co-moulded ontoeach side of the elbow 72W. The elbow gripping regions 72W assist: (1)gripping of the elbow 72W during manufacture, and/or (2) removal of theelbow 72W from the frame 4W by a patient or clinician.

5.9.2 Soft Touch

Other mask embodiments include one or more soft touch surface(s)co-moulded to the mask frame. The soft touch surface(s) feels nicer andless clinical to a patient than a hard surface(s) (e.g. polycarbonate).By varying the thickness and hardness of a soft touch surface, a rangeof different feels may be provided. Other parts of respiratory masks mayalso include soft touch surfaces such as the headgear clips or foreheadsupport.

5.9.3 Branding

Co-moulded elastomer regions also provide suitable surfaces for theplacement of product or company branding or logos, e.g., “ResMed” couldbe spelled out by co-moulding onto various mask components such as theframe, headgear, forehead support, elbow, etc. In one embodiment, thebranding indicia is embossed into the elastomer or the elastomer formsthe branding indicia. It should be noted that any one elastomer regioncould be used for a multiplicity of purposes, such as more than one ofgripping, soft touch and branding. The elastomer could also be colouredto improve aesthetics, or for branding purposes etc.

5.10 Other Overmoulding Applications for Masks 5.10.1 Mask VolumeReduction Bladder

Referring to FIG. 39, a mask volume reduction bladder (MVRB) 156Y may beincorporated into a mask frame 4Y by overmoulding an expandable pocketonto an interior surface 158Y of the frame 4Y, and more particularly,overmoulding a peripheral edge 160Y of the pocket to the interiorsurface 158Y of the frame 4Y. The bladder 156Y is positioned andconfigured such that it is expandable to occupy at least a portion ofthe gas dead space within the mask. In this particular embodiment, thebladder walls are made from a thin sheet of silicone (0.1-0.6 mm thick).

The bladder may have elastic properties and in an alternative embodimentmay be configured within a recess in the frame instead of on an interiorsurface of the frame. In one variation, the bladder volume is in fluidcommunication with an interior volume of the frame via a flap valve orother suitable valve. In yet another variation, the frame includes anair passageway between the interior volume of the frame and the interiorvolume of the bladder.

In another embodiment, the bladder inflates and deflates responsive tothe breathing cycle of the patient, reducing the volume required to bedisplaced by the patient's lungs during exhalation. In yet anotherembodiment, the bladder deflates during exhalation to increase thevolume and thus reduce the expiration pressure peak and subsequently thework of breathing. In another embodiment the bladder is co-moulded to anouter surface of the frame and an interior portion of the bladder is influid communication with an inner region of the frame (e.g. via anaperture in the frame). During exhalation the bladder can expand andthus reduce the expiration pressure peak and subsequently the work ofbreathing.

5.10.2 Removable Oxygen Sensing Cannula

FIG. 40 shows a frame 4Z of a respiratory mask incorporating oxygencannulae 162Z that are formed by overmoulding silicone to an interiorsurface of the frame 4Z. The cannulae 162Z can be peeled away from theframe 4Z starting at the cannula exit apertures 164Z such that the exitapertures 164Z are positioned directly beneath a patient's nares. Thecannulae 162Z are in fluid communication with frame ports 166Z to whichan oxygen delivery conduit (not shown) or gas receiving conduit (notshown) may be attached. A gas receiving conduit might be used to receiveexhaled breath in order to detect levels of different gases (e.g.oxygen) in the exhaled breath. The frame ports 166Z are sealed by plugswhen the cannulae 162Z are not in use and the cannulae 162Z may becompletely removed (torn off) the frame 4Z. The plugs may take the sameor similar form to those described in Section 5.8.

5.10.3 Humidifier Tub Seal [U.S. patent application Ser. No. 10/533,940]

U.S. patent application Ser. No. 10/533,940 is incorporated herein byreference in its entirety. Referring to FIGS. 41-43, a ResMed S8 flowgenerator 168AA is shown comprising a humidifier 170AA. The humidifier170AA has a lid 172AA, an underside of which is shown in FIG. 42 andincludes a recess 174AA. FIG. 43 shows an elastomer seal 176AA that isadapted to fit in the recess 174AA.

The improvement over U.S. patent application Ser. No. 10/533,940 is thatthe elastomer seal 176AA is co-moulded to the lid 172AA about the airexit aperture 178AA. This overmoulding provides a stronger mounting ofthe seal 176AA to the lid 172AA than a mere mechanical interlock andalso ameliorates the problem of biological growth in crevices. Theovermoulding can be in the form of a full surface bond or a peripheralbond.

The improvement ameliorates difficulties sometimes encountered inmounting the seal 176AA on the lid 172AA and makes the step ofconnecting the two parts during assembly obsolete.

5.11 Elbow-to-Frame Seal

FIG. 44 shows a full face mask 2.1 having a frame 2.2 and an elbow 2.3provided to the frame. Details of the overall mask are described inrelation to U.S. patent application Ser. No. 11/027,689, filed Jan. 3,2005, incorporated herein by reference in its entirety. A seal is formedbetween the elbow and the frame and may be formed on the frame or theelbow using the overmoulding techniques described herein.

FIG. 45 shows a seal 2.5 that is formed on an inner circumferentialportion of the elbow at the base of the frame inlet. FIG. 46 shows aseal 2.6 formed on an outer circumferential surface of the elbow. FIG.47 shows a seal 2.7 at the distal end portion of the inlet portion ofthe frame.

FIG. 48 includes an elbow with the seals from FIGS. 47 and 46 All of theseals 2.5, 2.6 and 2.7 can be formed on either the frame and/or theelbow. The seals help decrease leak while at the same time reducesqueak/squeal if the elbow is rotated relative to the frame.

5.12 Alternative Seal Designs

FIG. 49 is an exploded view of a test rig 3.1 including for testingseals that can be used with the elbow-to-frame connections describedabove. FIGS. 50-53 illustrate various seal geometries.

FIG. 50 shows a syringe-type seal 3.2 that is compressed to fit withinthe bore, but provides high sealing strength. FIG. 51 shows a bladestyle seal 33. While the main ridge 3.4 contacts the bore, the adjacentportions 3.5 may also contact the bore depending on the desired amountof rotation force required. FIG. 52 shows an axial flap seal 3.6 thatengages on an angled face 3.7 of the bore. FIG. 53 shows a rubber sealhaving a generally rectangular cross-section.

5.13 Mould

A mould for a respiratory mask or humidifier tub is provided in oneembodiment of this invention. The substantially rigid component mouldprovides the substantially rigid component with very small sealing rimsaround the periphery of the elastomer bonding region and the elastomermould has corresponding notches that form a tortuous path that isdifficult for the liquid elastomer or other material to flow through.FIG. 54 shows a sample rotating mould system 4.1 having a turntable 4.2that rotates about an axis 4.3. Turntable 4.2 includes a first mouldingstation 4.4 for moulding a first component, e.g., the substrate (e.g.,frame) and a second moulding station 4.5 for moulding a secondcomponent, e.g., the elastomer (e.g., cushion, pad, seal, etc.).

5.13.1 Mask Design to Facilitate Removal from Mould

The respiratory mask is designed such that its substantially rigidcomponents can be demoulded largely without undercuts. The elastomercomponents may be made by moulding tool structures that produceundercuts. The demoulding of the elastomer components can then be doneby elastic deformation of the elastomer components.

5.14 Fully Automated Mask Manufacture

An automated manufacturing process for a mask is another embodiment ofthis invention. The automated manufacturing process utilizesovermoulding to manufacture and/or bond appropriate components, incombination with at least one automated assembly step (e.g. fitting theelbow in the socket or attaching the headgear to the headgear clips).

5.15 Advantages 5.15.1 Cost Saving

Overmoulding reduces cost of goods. Components, the only function ofwhich is to hold two other components together are made redundant.Components can also be made from less material when the attachmentstructure is no longer needed.

To raise an order with a supplier costs money. There is the cost of thelabour of the purchasing officer, as well as the cost of transportingeach individual part to the company. Overmoulding allows companies tocombine two or more components into one, thus significantly reducing theassociated purchasing costs.

Overmoulding also reduces inventory costs. These are the costs a companyincurs to keep the components in its warehouse and then deliver them tothe production floor. In simple terms, half as many parts means half asmany transactions. Warehousing staff also have one less part to receiveinto stores and one fewer part to locate and move.

A mask with less parts also provides further cost savings by reducingthe amount of time it takes to assemble the finished product and/or thenumber of assembly steps. Overmoulding also eliminates secondaryoperations such as machining and use of adhesives.

5.15.2 Quality Improvement

Improving quality leads to further cost savings. For example, the costof rework which includes the cost of any materials scrapped, plus thecost of employing a worker to repair or replace a component may beavoided.

An automated overmoulding operation would reduce assembly errors sincefewer manual assembly steps are required.

Quality derived through use of overmoulding also reduces costs in termsof reducing disgruntled customers. For example, the often difficult stepof assembling a cushion to a frame utilizing a cushion-to-frame clip isavoided.

5.15.3 Sealing

Since flexible materials seal better than harder materials, the use offlexible materials to surface harder materials will allow better sealsto be formed. For example, improved sealing between the elbow and frame,and frame and cushion can be achieved.

5.15.4 Soft-Touch

A soft to touch surface generally feels nicer and less clinical than ahard surface to a patient. Varying both the co-mould thickness andhardness can produce a range of different feels.

5.15.5 Biological contamination can be removed by washing

Mask components that have been co-moulded according to some embodimentsof the invention can have biological contamination removed therefrom bywashing the mask. The reason for this is that the components areintegrally joined and thus the mask does not include any crevices thatcannot be cleaned within the normal course of washing.

5.16 Materials

Thermoplastic elastomers (TPEs), solid silicone rubbers and LiquidSilicone Rubbers (LSRs) are usually suitable materials for a flexibleco-mould. It has been found by the inventors that a thermoplasticelastomer with the following general properties may be particularlyadvantageous:

-   -   Hardness of approximately 40 ShoreA    -   High Tear strength    -   Resistance to cleaning chemicals (e.g. soap, detergents etc.)    -   Low compression set    -   Ability to withstand cleaning temperatures of 93 degrees Celsius    -   Low friction and low squeak    -   Biocompatibility (specifically—ISO 10993, parts 3, 5, 6, 10 &        11)    -   Good bonding to substantially rigid component    -   Good process control for high volume manufacture    -   Translucency    -   Low cycle time

The following materials have been found to exhibit some or all of theabove properties:

-   -   “Dynaflex® TPE Compounds” and “Versalloy®” made by GLS    -   “Santoprene™ Thermoplastic Vulcanizate” and “Santoprene™        Thermoplastic Vulcanizate” made by Advanced Elastomer Systems.    -   Silastic™ Silicone rubbers made by Dow Corning.    -   Elastosil™ Silicone rubbers made by Wacker.

Where solid silicone rubbers are used, resin transfer mouldingtechniques may be used for moulding of the flexible components.

Polycarbonate, polypropylene, trogamid (nylon) and pocan plastics areall suitable substantially rigid materials.

5.17 Other Variations

While the invention has been described in connection with what arepresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the invention. For example, any functionally suitable materialsmay be utilized in conjunction with this invention. Furthermore, theflexible and substantially rigid materials could have the same level offlexibility or resilience. In another embodiment, the substantiallyrigid material could be more flexible than the flexible material.

Also, the various embodiments described above may be implemented inconjunction with other embodiments, e.g., aspects of one embodiment maybe combined with aspects of another embodiment to realize yet otherembodiments, or additional embodiments can reside in a single element orportion thereof of any given embodiment.

In addition, while the invention has particular application to patientswho suffer from OSA, it is to be appreciated that patients who sufferfrom other illnesses (e.g., congestive heart failure, diabetes, morbidobesity, stroke, barriatric surgery, etc.) can derive benefit from theabove teachings. Moreover, the above teachings have applicability withpatients and non-patients alike in non-medical applications.

1. A respiratory mask for administering a breathable gas to a patient,the respiratory mask comprising: a first component formed from anelastomeric material; and a second component formed from a material thatis less flexible than the elastomeric material, wherein the firstcomponent is integrally formed onto the second component.
 2. Therespiratory mask as claimed in claim 1, wherein the integral forming issuch that the first component can be manually separated from the secondcomponent.
 3. The respiratory mask as claimed in claim 1, wherein theintegral forming is such that the first component is joined to thesecond component in an intimately adhering manner.
 4. The respiratorymask as claimed in claim 1, wherein the integral forming is carried outin an injection moulding tool.
 5. The respiratory mask as claimed inclaim 1, wherein the elastomeric material is an LSR material.
 6. Therespiratory mask as claimed in claim 1, wherein the second component isformed from a polycarbonate material.
 7. The respiratory mask as claimedin claim 1, wherein the first component is a sealing cushion.
 8. Therespiratory mask as claimed in claim 1, wherein the first component isan outlet conduit device.
 9. The respiratory mask as claimed in claim 1,wherein the first component is a forehead-contacting device.
 10. Therespiratory mask as claimed in claim 1, wherein the first component is aclosure device.
 11. The respiratory mask as claimed in claim 1, whereinthe first component is an articulated structure.
 12. The respiratorymask as claimed in claim 1, wherein the first component is a diaphragmdevice.
 13. The respiratory mask as claimed in claim 1, wherein thefirst component is a tubular body portion.
 14. The respiratory mask asclaimed in claim 1, wherein the first component is a breathing gas linesegment.
 15. The respiratory mask as claimed in claim 1, wherein thefirst component is a functional seal.
 16. The respiratory mask asclaimed in claim 1, wherein the first component is a stop device. 17.The respiratory mask as claimed in claim 1, wherein the first componentis a decoration or logo.
 18. The respiratory mask as claimed in claim 1,wherein the first component is a headband connection device.
 19. Therespiratory mask as claimed in claim 15 wherein the first component is asoft gripping pad.
 20. The respiratory mask as claimed in claim 15wherein the second component is a forehead rest mount.